The invention relates to automatic fabric washing machines of the vertical axis type and, more particularly, to an adjustable drive system for oscillating the agitator through a variable arc.
It is often desirable to be able to select different levels of energy input into a fabric or clothes washing machine. In the past variable energy input commonly was accomplished by the use of a multi-speed motor or by a multi-speed clutch connected between a single speed motor and the agitator. Both such approaches are relatively expensive and require complicated control circuitry for selecting the desired input speed. Other commercially available washing machines have multiple agitators. Generally a "regular" agitator is nested over a "gentle" agitator and effects the washing action. Upon removal of the regular agitator the smaller, gentle agitator effects a lower energy washing action.
Some prior art patents, such as U.S. Pat. Nos. 3,388,570 and 3,511,067 for example, show and describe agitator mechanism in which the exposed area of the agitator vanes in varied. Typically this is accomplished by varying the length of vane exposed to the liquid and fabrics in the machine. U.S. Pat. No. 3,213,651, assigned to General Electric Company, assignee of the present invention, discloses the use of a spring loaded mechanism connected between an input member and the agitator. As the input member is oscillated, the agitator oscillates only after the associated spring is fully compressed. U.S. Pat. No. 4,325,234, also assigned to General Electric Company, discloses a machine including a drive shaft oscillatable about a first axis and an agitator oscillatable about a second axis. A plurality of selectably engageable finger and slot arrangements oscillate the agitator through a selected one of a plurality of arcs in response to oscillation of the drive shaft through a predetermined arc.
Some of the mechanical arrangements for varying the energy input are relatively complicated while others place relatively large pressures on fairly small mechanical parts. None of these arrangements is totally satisfactory.
Therefore an object of this invention is to provide a new and improved agitation system for a washing machine.
Another object of this invention is to provide an improved agitation system in which the agitator may be driven through a shorter arc than the arc of the input drive member.
Yet another object is to provide such an improved agitation system in which a lost motion fluid drive is provided between the input drive member and the agitator.
Still another object is to provide such an improved agitation system in which the effectiveness of the lost motion fluid drive is selectably variable.
Another object of the present invention is to provide a new and improved agitation system for a washing machine in which the agitator selectively is connected to the input drive means for conjoint oscillation therewith and is disconnected from the input drive means.